1. Field of the Invention
The present invention concerns an evaluation method for a series of image data sets of a region of an organism, wherein the series of image data sets was acquired while the acquired region of the organism moved due to breathing and heartbeat.
The present invention furthermore concerns a computer program that embodies code that can be executed directly by a computer to execute such an evaluation method.
The present invention furthermore concerns a computer that is configured to execute such an evaluation method during operation.
2. Description of the Prior Art
An important diagnostic application of cardiac imaging is to reveal areas in the myocardium that have a reduced functional capacity. In particular, nuclear medical imaging with the modality is known as SPECT (Single Photon Emission Computed Tomography) has been established for this purpose. Furthermore, in the future it is expected that nuclear magnetic resonance tomography for such diagnostic applications will be increasingly used. Nuclear magnetic resonance tomography offers the advantages of a significantly better spatial resolution and the delivery of additional functional information, for example a prognosis of the recovery of the regional contraction capability of the heart, the mobility or the contraction-triggering state of the cardiac wall, etc.
An additional advantage of the nuclear magnetic resonance tomography is that ionizing radiation does not need to be used.
In the prior art, to show the functional capacity a contrast agent (for example a gadolinium agent) is administered and the tissue is examined after a certain time (in the minute range) with an appropriate measurement sequence. The contrast agent is in an enriching state at the points of the cardiac muscle at which the perfusion of the cardiac muscle is severely limited only after a delay following the time of administration (injection). The diseased area is therefore shown with higher signal than healthy tissue. This procedure is known in the prior art as “delayed enhancement”.
A different acquisition method based on nuclear magnetic resonance methods is known as SPAMM (SPAtial Modulation of Magnetization). In this method an organized grid or stripe pattern is impressed on the cardiac region. In this case a reduced mobility of the myocardium appears in a deformation of the stripe or, respectively, grid structure within the time-resolved interval between two heartbeats.
The evaluations of the prior art are problematical because the region of the organism to be examined is moved. In particular, two superimposed movements are normally present, namely the lung movement induced by the movement of the diaphragm, and the heartbeat and the resulting movements caused thereby. Nearly all acquisition methods of the prior art are based on a movement-synchronized data acquisition, for example prospective or retrospective triggering and/or gating. A shortening of measurement time by an acquisition while the breath is being held is possible in some but not all cases.